Enables single-stranded DNA binding activity. Involved in positive regulation of DNA replication. Acts upstream of or within several processes, including hematopoietic or lymphoid organ development; replicative senescence; and telomere maintenance via telomere lengthening. Located in chromosome, telomeric region and nucleus. Part of CST complex. Is expressed in genitourinary system; mesonephric tubule; mesonephros; and nephric duct, metanephric portion. Orthologous to human CTC1 (CST telomere replication complex component 1). [provided by Alliance of Genome Resources, Apr 2022]